The current research program was designed to further our knowledge about the nature of schizophrenia by a prospective, longitudinal, investigation of the following questions about schizophrenic psychosis and schizophrenic cognition. 1) What is the longitudinal course of schizophrenic thought disorders? Are thought disorders primarily symptoms which persist when the patient is in the recovery phase? 2. What are the essential or primary features which are always present in schizophrenic thought disorders? What underlying factors influence schizophrenic thought disorders? 3. Can thought disorders and/or psychotic symptoms (such as first-rank symptoms, delusions or hallucinations) identify a nuclear or "true" schizophrenic subgroup, with a very negative clinical course? 4. What is the long-term course of psychotic distortions (first-rank symptoms, delusions, etc.) and how important are they as characteristics of schizophrenia? 5. What is the longitudinal course of adjustment in modern-day schizophrenia? The research involves a multi-faceted longitudinal investigation of thought disorders, first-rank symptoms, and other psychotic symptoms, and major components of adjustment over time, using a battery of structured interviews, performance tests, cognitive measures, personality inventories and behavioral ratings. Two samples of schizophrenic and nonschizophrenic patients are being assessed at five time periods, lasting up to eleven years for one subsample. Patients are evaluated at the acute phase, during partial recovery, and followed up at various phases during the post-hospital period, for disordered thinking and psychotic symptoms. They also are assessed for neurotic and affective symptoms, rehospitalization, personality variables, and social and work adjustment. The data are used to evaluate a number of theories about prognostic factors, disordered cognition, and psychosis, and to assess the long-term clinical course and level of adjustment in modern day schizophrenia.